Cover The Ground: Naturally

by Cindy Gilberg

Ground cover plantings can be tremendous problem-solvers, offering sustainable options to mowed lawn and pavement. Ground covers unify the scene by visually tying together different areas within a landscape, providing textural transitions from mowed lawn to other plantings. While most gardeners think of ground covers as low-growing perennials, the definition literally means plants that cover the ground, so a mass planting of shrubs combined with perennials and/or grasses functions as ground cover. Imagine no longer mowing a steep slope or trying to grow lawn grass in shade or in wet soil. Ground cover plantings, in combination with other plants, are viable options for erosion control and rainscaping. Turn a problem into an opportunity—create a beautiful and diverse landscape feature using Missouri native plants that are not only well-adapted to our climate but also add much needed habitat for birds, butterflies and other creatures. Once established, native ground cover plantings can crowd out weeds, providing landscape features that do not require fertilizer, mowing, watering or pesticides.

One problem area for gardeners is shade—many scratch their heads, curse the shade, and say that nothing will grow there. Yet a walk in Missouri’s woodlands reveals a diverse bounty of woodland plants. Encompass groupings of shade trees to create an island bed with a few small trees (serviceberry, dogwood or redbud) and some shrubs (for example, wild hydrangea). Fill in with shade-loving perennials, for example, ferns, Indian pink (Spigelia marilandica), wild Geranium or Solomon’s seal (Polygonatum biflorum). Add the finishing touch with ground cover species that offer a low maintenance solution while visually defining and unifying the scene. This list includes oak sedge (Carex albicans), wild ginger (Asarum canadense), alum root (Heuchera parviflora) and golden groundsel (Senecio obovatus). This protects exposed tree roots that often get cut by mower blades, is healthier for the trees than ‘tree donuts’ of mulch and offers an aesthetic break from lawn. A reduction in the amount of mowed lawn adds a savings of both time and fuel not spent mowing. Save lawn for areas where it is easier to grow, mow and for use as pathways.

Ground covers are incredible problem solvers for steep slopes. It is dangerous to mow and erosion is often an issue. Among some of most useful native plants for this situation (in full-part sun, dry soil) are aromatic aster (Symphiotrichum oblongifolius), prairie dropseed (Sporobolis heterolepsis), blue false indigo (Baptisia australis), slender mountain mint (Pycnanthemum tenuifolium) and American feverfew (Parthenium hispidum). Add in butterfly milkweed and blazing stars for splashes of color.

Perhaps your property has low areas that remain wet. Sedges and rushes, such as palm sedge (Carex muskingumensis) and soft rush (Juncus effuses), thrive in moist soil and can be used as ground cover. Shining bluestar (Amsonia illustris) is a spring-blooming, four foot tall perennial that can function as a hardy ground cover. A solid-growing groundcover for wet sun is southern blueflag iris (Iris virginica) for additional color in spring and spiky leaves throughout summer and fall.

As you begin, here are a few tips to keep in mind. Never till under trees as this damages surface roots causing slow decline and death of trees. Instead, a layer of compost/soil, about 6” deep, can be spread over the surface under trees—don’t pack it around tree trunks. Shorter, shallow rooted plants such as wild ginger (Asarum canadensis), daisy fleabane (Erigeron pulchellum) and crested iris (Iris cristata) grow happily in this layer.

As with any garden design, pay particular attention to foliar texture by combining plants with textural contrast in mind. Short sedges and ferns offer a fine texture that blends well with the larger texture of wild ginger, groundsel and alum root. Always match the site to a plant list that will thrive in that condition (i.e., sun vs. shade, dry vs. wet) for best success.

Cindy Gilberg is a Missouri native and horticulturist whose work includes design and consulting, teaching and writing. Much of her work focuses on native plants, habitat gardens and rain gardens. Cindy’s projects include work at Shaw Nature Reserve and its Native Plant School, the Shaw Professional Landscape Series and the Deer Creek Watershed Alliance.

You can contact Cindy at 314-630-1004 cindy.gilberg@gmail.com.